Strategies for Biochemical and Pathologic Quality Assurance in a Large Multi-Institutional Biorepository; The Experience of the PROCURE Quebec Prostate Cancer Biobank

Abstract

Well-characterized, high-quality fresh-frozen prostate tissue is required for prostate cancer research. As part of the PROCURE Prostate Cancer Biobank launched in 2007, four University Hospitals in Quebec joined to bank fresh frozen prostate tissues from radical prostatectomies (RP). As the biobank progressed towards allocation, the nature and quality of the tissues were determined. RP tissues were collected by standardized alternate mirror-image or biopsy-based targeted methods, and frozen for banking. Clinical/pathological parameters were captured. For quality control, two presumed benign and two presumed cancerous frozen, biobanked tissue blocks per case (10/site) were randomly selected during the five years of collection. In a consensus meeting, 4 pathologists blindly evaluated slides (n = 160) and graded quality, Gleason score (GS), and size of cancer foci. The quality of tissue RNA (37/40 cases) was assessed using the RNA Integrity Number. The biobank included 1819 patients of mean age: 62.1 years; serum PSA: 8ng/ml; prostate weight: 47.8 g; GS: 7; and pathological stage: T2 in 64.5%, T3A in 25.5% and T3B in 10% of cases. Of the 157 evaluable slides, 79 and 78 had benign and cancer tissue, respectively. GS for the 37 cancer-positive cases were: 6 in 9, 7 in 18 and > 7 in 10 and, in most instances, in concordance with final GS. In 40% of slides containing cancer, foci occupied ‡ 50% of block surface and 42% had a diameter ‡ 1 cm. Tissue was well preserved and consistently yielded RNA of very good quality with RNA Integrity Number (RIN) > 7 for 97% of cases (mean = 8.7 -0.7) during the five-year collection period. This study confirms the high quality of randomly selected benign and cancerous fresh-frozen prostate tissues of the PROCURE Quebec Prostate Cancer Biobank. These results strengthen the uniqueness of this large prospective resource for prostate cancer research.

Quality assessment and preservation of RNA from biobank tissue specimens: a systematic review

“…Of the 15 studies assessed, 13 investigated quality of tissue biospecimens from various cancers, including pancreatic, colorectal, breast, bladder, ovarian, and head and neck 17–29. Overall, 93% of studies reported at least two diagnostic and two predictive measures of quality,12 17–24 26–30 with the majority of studies (53%) reporting at least six of the nine diagnostic and/or predictive quality measures 12 18 20–22 27–29. Moreover, of those, 25% of studies reported at least seven of the nine measures of interest 21 28…”

“…In addition, the majority of these studies (73%) reported storage of tissue biospecimens at −80°C,12 17–19 22–24 26–29 30 despite best practice guidelines suggesting tissue biospecimens should be stored long term at −196°C 14. Transit time from surgical resection to time of cryopreservation was reported by 9 of 15 studies, with times ranging from instantaneous fixation in theatre to 72 h 12 18 21–24 27–29. However, transit temperature was recorded infrequently, with only 27% of studies recording this outcome measure19–21 28 and the majority (3/4) transporting specimens at 4°C 20 21 28…”

“…Furthermore, 73% of studies assessed tissue biospecimen morphology12 17 18 20–22 24–29 as well as 47% of studies assessing biospecimen quality for downstream analyses 12 19 20 23 26 28 30…”

“…Eleven studies performed histological assessments of tissue biospecimens 17 18 20–22 24–29. Of these, six studies described cellular and architectural integrity, and also reported the percentage of tumour cells and cellular homogeneity of specimens 17 18 21 25–27.…”

Developing in vitro models of human ductal carcinoma in situ from primary tissue explants

“…Half the tissue was de-identified and handed off to lab personnel for tissue culture. The second half, known as the ''mirror image,'' was read by the pathologist and then stored in the tissue bank as a FFPE block with a corresponding hematoxylin and eosin-stained slide cut from that block [23,24].…”